Robotic mower navigation systems direct travel of robotic mowers within yards or to specific locations or portions of yards by measuring distances traveled from known references (e.g., charging stations) following boundary wires. Robotic mower navigation systems may include electronic control units that collect odometry data by measuring wheel rotation. However, wheel slippage caused by traction lost on wet grass, loose dirt, side hill compensation to drive in a straight line, or other reasons may result in significant distance measurement errors over typical boundary wires. Distances measured by odometry may not match actual distances traveled by robotic mowers, and it is challenging to predict the exact paths traveled by robotic mowers. As a result, robotic mower navigation systems lack high accuracy to navigate to specific locations or portions of yards within boundary wires, and also lack high precision to reliably and repeatably navigate to such locations or areas. A robotic mower navigation system is needed that does not use odometry and is not required to predict the exact travel path of a robotic mower.
To achieve high accuracy and/or precision to deploy robotic mowers to specific locations or areas, some robotic mower navigation systems include global positioning systems (GPS), radio or light tags, RFID, ultrasound/laser/radio triangulation, or simultaneous localization and mapping (SLAM). However, these navigation systems are relatively expensive. A robotic mower navigation system is needed that is inexpensive and achieves high accuracy and high precision to navigate to specific locations or portions of yards within boundary wires.